Horizontal diffusion furnace

Abstract

Abstract PURPOSE:To make temperature within a core tube uniform in the vertical direction by providing a sub-heater or condenser tube within an outer cylinder for adjusting difference in temperature between the upper and lower parts within the core tube. CONSTITUTION:A horizontal diffusion furnace comprises an outer. cylinder 4, within which there are arranged a heat insulating material 3, a main heater 1 wound spirally and a core tube 2 sequentially in that order. Further, a sub- heater 6 is provided particularly under the main heater 1. When current is supplied to the main heater 1 through a main heater terminal base 5, difference in temperature is caused between the upper and lower parts within the core tube. By supplying current to the sub-heater 6 through a sub-heater terminal base 7, however, such difference in temperature within the core tube can be adjusted so as to make the temperature uniform. Accordingly, semiconductor substrates to be heat treated within the core tube are allowed to have a uniform temperature in the upper and lower parts of the core tube. As a result, oxide films for example can be formed in a constant thickness on the surfaces of the semiconductor substrates.

Inventors

• 👤 Katsuyuki Sasahara
• 👤 笹原　勝之

Bibliographic Details